Some existing systems copy data from a computing device to a storage media for backup purposes. These existing systems operate responsive to a user-initiated request, or operate automatically before an update is installed on the computing device. To ensure the authenticity of the backup data, the existing systems digitally sign the backup data. In such systems, a digital key signature is stored with the backup data on the storage media. However, the key may be compromised (e.g., replaced or modified) by any user or other party as the key is stored with the backup data, and is read-write accessible by the user.
Other systems employ a server to securely store the key. This solution, however, is not feasible in computing systems that lack access to a central key repository. For example, when restoring data to a mobile computing device, the mobile computing device may not have network connectivity to access the central key repository. Without the ability to perform authentication, the user may apply unauthorized images or store unauthorized data on the mobile computing device.